1. Field of the Invention
The present invention relates to a technique for controlling an image forming apparatus that can perform print output processing based on image data read from a document.
2. Description of the Related Art
From the viewpoint of effective use of resources, there is a conventional image forming apparatus that can delete any blank page(s) if included in a read document to prevent useless recording of blank page(s) or prevent useless print output of the blank page(s).
A conventional image forming apparatus discussed in Japanese Patent Application Laid-Open No. 10-229484 has an automatic blank page deletion function, which is capable of detecting a blank page included in a read image and deleting image data corresponding to the detected blank page.
On the other hand, in many cases, when users of the apparatus use document sheets for copying operations, it is desired to determine the print output layout by fixing the relationship between consecutive pages of a document image, such as a mutual relationship between front and back surfaces of a document sheet or a mutual relationship between right and left pages in an opened state in a bookbinding printing.
Therefore, if the conventional image forming apparatus deletes blank pages according to the blank page deletion function, page numbers of respective pages may change undesirably. For example, pages to be printed on the front and back surfaces of a same sheet may be separately printed on different sheets. Further, pages to be printed on the right and left (or upper and lower) sides in an open layout may be erroneously printed on the front and back surfaces of a print sheet.
For example, in a case where two-sided printing of a two-sided document is performed, if a specific one page is deleted, the page numbers of the following pages are decremented by one. As a result, odd page numbers are changed to even page numbers and even page numbers are changed to odd page numbers. More specifically, in such a case, the page image previously positioned on the front (rear) surface of a document is printed on a rear (front) surface of a print sheet.
Further, the page image previously positioned on the right (left) side of an opened-state document is printed as a left (right) page of a print sheet in an opened state. Moreover, the page image previously positioned on the upper (lower) side of an opened-state document is printed as a lower (upper) page of a print sheet in an opened state.
As described above, depending on the number of pages to be deleted or an output layout method, users of the image forming apparatus may not be able to obtain printed output results as intended.